Author Contributions: Dr Schmajuk had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Schmajuk, Trivedi, Yelin, Yazdany.
Acquisition of data: Schmajuk, Yazdany.
Analysis and interpretation of data: Schmajuk, Trivedi, Solomon, Chakravarty, Trupin, Yazdany.
Drafting of the manuscript: Schmajuk, Yelin, Yazdany.
Critical revision of the manuscript for important intellectual content: Schmajuk, Trivedi, Solomon, Yelin, Chakravarty, Trupin, Yazdany.
Statistical analysis: Schmajuk, Yelin, Trupin, Yazdany.
Obtained funding: Schmajuk, Yelin, Yazdany.
Administrative, technical, or material support: Trivedi, Yazdany.
Study supervision: Solomon, Chakravarty, Yazdany.
Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Trivedi reports receipt of compensation from Merck (for editing a chapter of the Merck Manual) and from the Pzifer (for receiving a Health Policy Scholars Award from the Pzifer Foundation). Other authors reported no potential conflicts.
Funding/Support: Funding was provided by the American College of Rheumatology/Research and Education Foundation Physician-Scientist Development Award; National Center for Research Resources (5-M01-RR-00079); Rosalind Russell Medical Research Center for Arthritis; National Institutes of Health (R01-AR-44804); State of California Lupus Fund; Arthritis Foundation; Agency for Healthcare Research and Quality; and National Institute of Arthritis and Musculoskeletal and Skin Diseases (grant numbers: 1-R01-HS-013893, P60-AR-053308, K24-AR-AR055989, and R01-AR-056215).
Role of the Sponsor: The funding organizations had no role in the design and conduct of the study, in the collection, analysis, and interpretation of the data, or in the preparation, review, or approval of the manuscript.
Additional Contributions: We would like to thank Alan Zaslavsky, PhD, Department of Health Care Policy, Harvard Medical School, for sharing his case mix adjustment macro. Dr Zaslavsky was not compensated for this contribution.